Lubrication



M. FAIRLIE ETAL Nov, 11, 1941.

LUBRICATION Filed July 15, 1938 /2 /6 20 24- 28 J2 36 40 44 46 Hoz/ms /A/ M40/wf 4 Mayu-"5T AAM M ATTORNEYS Patented Nov. 11, 194.1 i

NUNITED vsfm'lls' S PATENT lOFFICE LUBRICATION Matthew Fairle and Leonard E. Beare, Hammond, Ind., assignors to Sinclair Refining Company, New York, N. Y., a corporation of Maine Application July 15, 1938, Serial No. 219,459

7 Claims.

As described and claimed in our cao-pending application, Serial No. 219,457, filed July 15, 1938, we have discovered that if petroleum-base oils, either compounded or uncompounded, are heated substantially above normal crank case temperature and passed in contact with a solid selected from the'group consisting of the alkaline earth metals and their inorganic compounds, the tendency for the oil to deteriorate during service is reduced and difculties due to ring-sticking, etc., are inhibited. In our co-pending application, Serial No. 219,458, filed July 15, 1938,`we have described and claimed a further discovery, to wit, that mixtures containing more than one of the three alkaline earth metals or their inorganic compounds, are more effective as a contact mass V,for inhibiting deterioration of petroleum base oils and inhibiting corrosion of metals with which the oils come in contact than av contact mass containing only one of the alkaline metalsinv jelemental or `combined form'. third rio-'pending application, Serial No. 219,456,

earth led July 15, 1938, we have described and claimed In a` iicial effects of such treatment are, however, augmented at elevated temperatures. Our invention, therefore, contemplates a method of treating a petroleum-base lubricant which comprises passing said lubricant containing an aluminum soap in repeated contact with a solid selected from the group consisting of the alkaline earth metals and inorganic compounds thereof. Preferably, the solid is in porous or finely divided' form so that the oil may -be forced through it. Thus, the solid or contact mass may be in the form of a filter disposed in the lubricating system of an internal combustion engine, the oil being pumped out of the service zone of the system, for example, the crank case `of the engine through the filter and back linto the service zone.

All of the alkaline earth metals, i. e., calcium, barium, and strontium, may be employed in the ,practice of our invention either in metallic form or as inorganic compounds, for example the hydroxides, oxides, carbonates and carbides. The hydroxides are preferable from an economic standpoint, because they are both eflicacious and relatively inexpensive.

In the preferred practice of our invention, the oil containing the aluminum soap is withdrawn from a service zone, for example the crank case of an internal combustion engine, brought to optimum treatment temperature, whichin general isin excess of about 240 F. and preferably about 300 F., and then circulated back to the service zone through a contact mass of porous our discovery that contact masses of alkaline v earth metals ory inorganic compounds thereof hydroxide` of calcium, barium or strontium. In general, the higher the rate of circulation, the better are the results obtained, but good results have obtained witha porouscontact'fmass "1 weighing about 200 gm, grams (or about 20% are very effective in preventing deterioration of and corrosion by petroleum-base oils containing a soap of an alkaline earth metal even at normal crank case temperatures and below. By analogy, it would seem that aluminum or its inorganic compoundsrmight be used as a contact mass to inhibit deterioration of and corrosion by petroleumv base lubricating oils containing aluminum soaps. We have discovered, however, that aluminum and its compounds are not useful in this respect, but that the deterioration of and corrosion by petroleum oils containing aluminum soaps are inhibited substantially even at relatively low temperatures if the oil is brought repeatedly into contact with a solid selected from the group consisting of the alkaline earth metals and inorganic compounds thereof. The beneof the weight of the oil in circulation) through which the oil was circulated at the rate of 150 ccs. perminute (or approximately 15% of the total oil `in the system per minute).

\The beneficial actionof the contact mass apparently is directly proportional to the exposed sur-face of the active ingredient, for example, strontium hydroxide. Consequently, the contact mass should be as porous or as finely divided as possible, consistent with the limitations imposed by the necessity of forcing the oil through the mass by a reasonable degree of pressure and without having thel particles so fine that a substantial amount ofV them are entrained by the oil and carried into the service zone where, conceivably, they may bring about abrasion. In

general, however, we have found that it is not desirable to employ a mass in which a substantial proportion of the particles are larger than pea size or smaller than about 14 mesh.

The contact mass may be in the form of a coherent body of particles that have been caused 5 to adhere or cohere in any appropriate manner, or it may be in the form of loose particles of appropriate size retained in a pervious-walled n Fig. 2 is a graph of results obtained in testing cadmium-silver bearings in a laboratory bearing corrosion test machine lubricated With a petroleum-base oil containing an aluminum soap, in one case employing a contact mass of calcium hydroxide through which the oil was circulated, and in another case which was similar in all respects except that no contact mass was employed.` Passing now to a consideration of the drawing, the filter of Fig. 1 comprises a cylindrical metal shell I having a cover plate I I bolted to a flange I2 around the top of the shell with a gasket I3 interposed between the ange and the top to insure a tight joint. Disposed concentrically within the shell is a canister I4 made from perforated Monel metal screen or other pervious corrosionresistant material. The canister is annular in form with an enclosing top portion I5 so that it surrounds a space I6 immediately above an outlet pipe IVI. An inlet pipe I8 is provided in the outside of the shell and the space in the shell around the canister is lled with cotton wool I9. The inside of the canister is filled with a pervious mass of an inorganic solid 20, containing calcium, strontium or barium in elemental or combined form. Thus, the canister may be packed with twisted calcium foil, but for economic reasons, it is desirable to ll the canister with ne lumps (say 8 to 14 mesh) of the hydroxide or carbide of an alkaline earth metal or a mixture of the two. An oil containing aluminum soap is withdrawn from the crank case of theengine and by means of a pump forced through the cotton wool and the contact mass of alkalin arth metal or inorganic compound thereof to he outlet. From the outlet the treated `oil is returnedv to the crank case s o that a repeated circulation is set up.

The tendency of the contact mass to escape from the lter is relatively slight. Lumps of calcium hydroxide and the like are relatively fri-- able in the air, but when once wetted with oil there is little tendency for them to break apart. However, the cotton wool is provided as a safeguard against the circulation of calcium hydroxide and other solids through the engine. The cotton also serves to distribute the oil through the filter and thus prevent channeling.

Asa furtherprecaution against the escape of the contact mass into the engine, it is advisable to soak the mass with oil prior to installing the filtering on the engine. This may be done conveniently by pumping voil through the mass, so

tion in reducing corrosion of cadmium-silver bearings by a petroleum base oil containing an hydroxide was placed in .the filter so that the oil that fine` particles which tend vto escape maybe removed prior to placing the mass in service in the lubricating system.v i

Fig. 2 illustrates the effectiveness of our inven- 2. In the operation of a system for lubricating A was passed in repeated circulation with both bearing and contact mass. In both cases, the oil was circulated at a temperature of 300 F. for 32 hours, when the temperature was raised to 350 F., and 'the circulation continued for 8 hours more. In both cases the quantity of oil ln circulation was 1.0 liter, and it was circulated at the rate of ccs. per minute.` In the `second case, the Weight of calcium hydroxide in the filter was 200.0 grams.

As shown in Fig. 2, corrosion of the cadmiumsilver bearings by the oil containing the aluminum soap was very marked when no contact'mass was employed and increased markedly when the temperature was increased. On the other hand. corrosion was practically completely inhibited by the use of the contact mass. Moreover, the contact mass is effective in reducing sludging and the formation of tars and asphaltenes so that ring-sticking, piston lacquering and other mechanical diiiiculties'caused by deposition of such materials tend to be diminished greatly.

We claim:

1. In the operation of a system for lubricating surfaces with a petroleum base lubricating oil containing an aluminum soap which involves repeated contacting of said oil from a body thereof with the surfaces to be lubricated and circulation of said oil through a treating zone, the improvement which comprises bringing the oil in said treating zone in contact with a solid selected from the group consisting of the alkaline earth metals and inorganic compounds thereof at a rate sufficient to bring into contact with said solid an amount of oil equivalent to a substantial part of said body of oil per minute, and controlling the temperature of the oil in said treating zone to maintain the oil in contact with said solid at a temperature approximating 240- the bearing surfaces of ,an internal combustion engine with a petroleum base oil containing an aluminum soap which involves repeated contacting of said oil from a body thereof with the bearing surfaces of said engine and circulation of said oil through atreating zone, the improvement `which comprises passing the oil containing the aluminum soap in said treating zone through a vporous mass of a solid selected from the group consisting of the alkaline earth metals and inorganic compounds thereof at a rate sufficient to bring Into contact with said solid an amount of oiI equivalent toa substantial part ofy said oil body perminutep and controlling the tempera-I ture of the cill in said treating zone tomaintain the oil in contactwith said solid at a temperature approximating 240-350 F. l

3. In the operation of a system for lubricating," surfaces with a petroleum base lubricatingfoilV containing an aluminum soap which involves repeated contacting of said oilV from a body there! lation of said oil through a treating zone, the improvement which comprises passing the oil in said treating zone through a porous mass of a solid selected from the group consisting of the alkaline earth metals and inorganic compounds thereof at a rate -suiiicient to bring into contact with said solid an amount of oil equivalent to a substantial part of said oil body per minute, and controlling the temperature oi the oilin said treating zone to maintain the oil in contact with said solid at a temperature approxit mating 300 F.

` 4. In the. operation of a system for lubricating surfaces with a petroleum base `lubricating oil containing an aluminum soap which involves the repeated contacting of said oil from a bod? thereof with the surfaces to be lubricated and circulation of said oil throughy a treating zone, the improvement which comprises bringing the 2o oil in said treating zone in contact with a solid selected from the group consisting of the alkaline earth metals and inorganic compounds thereof at a rate suiilcient to bring into contact with said solid an amount of oil equivalent to at least about 15% of said oil body per minute and maintaining the oil at an elevated temperature while in contact with said solid.

5. In the operation of a system for lubricating surfaces` with apetroleum base lubricating oil containing an aluminum soap which involves repeated contacting of said oil from a body thereof with the surfaces to be lubricated and circulation of said oil through a treating zone, the improvement which comprises bringing the oil in said treating zone in contact with a porous body containing substantial proportions of calcium hydroxide at a rate sumcient to bring into contact with said porous body .an amount of oil equivalent to a substantial part of said oil body per minute,` and controlling, the temperature of V v 2,262,529 -of with the surfaces.' to be' lubricated and circui the oil in said treating,A zone to maintain the oil in contact with said porous body at a temperature approximating 240-350 F.

6. In the operation of a system for lubricating y a moving part of a machine with a petroleum base lubricating oilv containing aluminum soap which involves repeated contacting of said oil from a body thereof with the moving parts to be lubricated and circulation of said oil through a treating zone while in service, the improvement which comprises bringing the oil containing aluminum soap in said treating zone into Vcontact with a porous body containing a substantial proportion of barium hydroxide at a rate sufficient to bring' into contact with said porous body an amount of oil equivalent to a substantial part of said oil body per minute, and conu trolling the temperature of the oil in said treating zone to maintain the oil in contact with said porous body at a temperature approximating 240350 F. g t

7. In the operation of a system for lubricating a moving part of a machine with a petroleum base vlubricating oil containing aluminumsoap lwhich involves repeated contacting of said oil fromy a body thereof with the moving parts to be lubricated and circulation of said oil through a treating zone while in service, the improvement which comprises bringing the oil containing aluminum soap in said treating zone into contact with a porous body containing a substantial proportion of strontium hydroxide at a rate sumcient to bring into contact with said porous body an amount of oil equivalent to a substantial part oi said oil body perminute, and controlling the temperature of the oil in said l treating zone to maintain the oil inpontact with said porous' body at a temperature approximat.

ing 240350 F.

LEONARD E. BEARE. 

